An enhanced precipitation accumulation algorithm for radar data

Conventional precipitation accumulation algo- rithms for radar data usually add up instantaneous precipita- tion intensity fields multiplied with the time interval between the data samples. This method does not take into account the propagation and development of the precipitation systems in the time between the data samples. As a consequence, the derived horizontal distribution of precipitation accumulation gives wrong results; in particular for small-scale fast-moving cells, when a clustering appears in the accumulation maps. This paper presents an algorithm which derives infor- mation about precipitation pattern movement and develop- ment using different tracking techniques or other radar data sources. The vector field information is used to combine in- stantaneous precipitation intensity fields of subsequent radar data samples by modelling the precipitation system develop- ment between the samples. The results demonstrate the improvement of the precipita- tion accumulation fields. In a case study, the results of differ- ent techniques are compared with rain gauge measurements. Computation time statistics are given which demonstrate that the different techniques can be used in real-time on standard PC stations.